Syringe



Patented Dec. 3, 1946 UNITED STATES SYRINGE Edith Holtman, New York, N. Y., assignor to Durex Products, Incorporated, New York, N. Y., a corporation of New York Application July 15, 1939, Serial No. 284,627

12 Claims.

This invention relates to syringes for applying medicaments in the form of liquid, powder or jelly to the interior of the body and more especially to a type of syringe in which a definite known amount or quantity of the medicament may be automatically expelled into the body.

An object of the invention is to provide a syringe in which the amount of medicament taken in, while of known value, may be readily varied to the end of injecting into the body a medica-' ment of any desired quantity within the limits of the capacity of the syringe.

A further object is to provide a syringe in which the amount of medicament drawn into or expelled from it may be readily varied without disturbing the relationship of the operating bulb with reference to thetube or barrel of the syringe.

Another object of the invention is to provide 20 a syringe of the type having a movable plunger with a rod or operating member adapted to frictionally engage the plunger so that the liquid, jelly or powder contained inthe syringe may be ejected forcibly and thus thoroughly distributed 2 over the bodily surfaces to be medicated. In further pursuance of this object means are provided whereby a frictional driving connection between the operating rod and the movable plunger may readilybe established.

30 Other objects and advantages will appear as the description of the particular physical embodiments selected to illustrate the invention progresses. For a better understanding of the invention, however, reference is made to the ac- 35 companying drawing in which like reference characters designate like parts throughout the several views, and in which:

Fig. 1 is a longitudinal sectional view of a syringe embodying the invention;

40 Fig.2 is a view of a syringe showing a modified form of the invention, the lower portion being shown in section and the upper portion in front elevation and;

Fig. 3 is a fragmentarysectional view showing 45 a modified form of connection between the adjusting rod and valve of the syringe.

Referring first to Fig. 1 the syringe is shown as comprising a substantially cylindrical tube I within the bore 2 of which is adapted for snug 50 sliding engagement a solid freely floating piston 3 made of any suitable rigid material. The lower end of tube I is provided with a constricted portion 4 for the purpose of engaging the piston 3 and preventing it from being ejected from the 55 tube. If desired, the constricted portion 4 may be interiorly threaded, as at 5, for a purpose to be described later. The upper end'of tube I is shown'as provided with an enlarged collar 6 to provide a shoulder I, a flexible hollow bulb 8. preferably formed of rubber, having its lower end 5 9 seated on the shoulder I and its exterior peripheral surface I 0 compressed against the interior surface of collar 6 to provide an airtight connection between the tube I and bulb 8.

In order to provide an adjustable stop to limit 10 the upward motion of piston 3, the upper end of bulb 8 is provided with a cylindrical aperture II in alignment with the axis of tube I. A rod I2 of slightly greater diameter than aperture II passes through the bulb 8 and has its lower end disposed for engagement by the piston 3, a suitable knob or handle I3 being provided on the upper end of rod I2. Means may be provided for centering the lower end of rod I2 within tube I,

that shown comprising a transversely extending disc I4 secured to rod I2 and slidable within the bore 2, the disc I 4 being provided with one or more apertures I5 to permit the passage of air against the piston 3 from the bulb 8. Means is provided to secure a frictional engagement between the rod I2 and piston 3 for a purpose to be later described. In the form of invention shown in Fig. 1, the lower end of rod I2 has a longitudinal slot It to provide a tip which gives slightly when it enters a central cylindrical recess I'l pro vided in the upper side of piston 3 to receive it. It is preferable to provide a small opening through the bulb 8 for the purpose of slowly venting air during the operation of the syringe, such an opening being indicated at I8. The tube I may be made of any suitable material but is preferably made of a transparent material such as glass, molded plastic material etc. so that its contents may readily be observed.

The embodiment of the invention shown in Fig. 40 2 is generally similar to that shown in Fig. 1 but in this form the lower end So of the bulb 8a fits around the upper end of tube Ia which is the same diameter as the main body of the tube. Also in this form, the lower constricted end 4a 5 of the tube is not provided with any screw thread but such a thread may be provided if desired. In order to provide a frictional connection to the piston 3a, its upper surface is provided with a cylindrical projection I9 adapted for frictional engagement with the interior wall 20 of a short piece of rubber tubing 2I which is firmly secured I to the lower end of the stop rod I2a by any suitable means, not shown.

In the form of connection shown in Fig. 3, the

tip of the stop rod lZb is tapered so as to present a conical surface 22 which is adapted to enter a similar shaped aperture 23 formed in the piston 3b. It will also 'be understood that instead of being conical shaped-the tip of rod l2b may have the shape of a parabola or any other curved surface which will provide a good frictional contact with the piston 3b.

In the operation of the syringe, the lower end of tube I is inserted into a vessel containing the medicament which it is desired to apply and which may be in the form of either a liquid, Jelly or powder. The bulb 8 is then compressed which causes the piston 3 to move to the end of tube l, as shown by dash lines in Fig. 1. Upon releasing the bulb 8 a partial vacuum is created above the piston 3, the pressure differential between its lower and upper surfaces causing it to move upwardly within the tube until it engages the tip of rod I2. A volume of the medicament corresponding to that of the portion of tube l traversed by the piston, is drawn into the tube and is ready for application to the interior of the body by the insertion of the end of the tube into the body cavity. The volume drawn into the tube may be readily adjusted to a definite, desired amount by adjusting the end of rod 12 to the proper position within the tube. The handle I3 facilitates this adjustment, as it may be readily grasped to slide the rod in either direction within the aperture l l in the bulb 8. By providing a frictional connection between the end of the stop rod and piston 3, the piston remains seated on the rod while the bulb 8 is being compressed until a sufficient air pressure is-built up in the tube above the piston to cause it to he suddenly and forcibly pushed off the tip of the rod I! or end of the tube 2| of Fig. 2. This sudden downward displacement of the piston expels the medicament from the end 40 of the tube with force causing it to reach and be well distributed over the surface requiring medication.

In case the medicament is supplied in a collapsible tube having a screw threaded top, such top is screwed intothe thread provided at the lower end of tube I, such as the thread 5, whereupon pressing the walls of the collapsible tube causes the medicament, such as a jelly, to enter tube l and displace valve 3 upwardly until it engages and is arrested by the stop rod. This automatically measures out the desired amount of medicament, the rod l2 having previously been set in the proper position to provide the desired dosage.

is compressed and the operation of the syringe is the same as above described.

I have described what I believe to be the best embodiments of my invention. I do not wish, however, to be confined to the embodiments shown, but what I desire to coverby Letters Patent is set forth in the appended claims.

I claim: 1. A syringe comprising a tube, a piston movable along the inner surface of the tube, means at one end of the tube for confining the piston against displacement from the tube, a flexible bulb connected to the other end of the tube, a stop within the tube adapted to engage the piston as the piston moves toward the flexiblebulb and an adiusting element having means external to both the tube and flexible bulb for adjusting the To apply the medicament, the bulb 8 longitudinally along the tube, the diameter of. the rod-like member being slightly greater than that of said aperture.

4. A syringe comprising a tube having a constricted lower end provided with a screw thread, a flexible bulb connected to the upper end of the tube, a piston movable along the inner surface of the tube, a stop within the tube and adapted to .limit the upward movement of the piston along the tube and an adjusting element having means external to both the tube and flexible bulb for adjusting the stop along the tube while the bulb and tube remain relatively fixed.

5. A syringe comprising a tube, a piston movable along the inner surface cf the tube, means at the lower end of the tube for confining the piston against displacement from the tube, a flexible bulb connected to the upper end of the tube and a rod passing through the flexible bulb and having its lower end disposed within the tube and adapted to engage the piston and limit its motion upwardly along the tube.

6. A syringe as set forth in claim 5 in which a transversely extending disc is provided within the tube, said disc being provided with a central bore adapted to receive the rod.

7. A syringe as set forth in claim 5 in which the upper side of the piston is provided with a bore and the lower end of the rod is adapted to frictionally engage the marginal surface of the bore.

8. A syringe as set forth in claim 5 in which the upper side of the piston is provided with a cylindrical bore and the lower end of the rod is slitted longitudinally and adapted to frictionally engage the marginal surface of the bore.

9. A syringe as set forth in claim 5 in which the upper side of the piston is provided with a tapered bore and the lower end of the rod is correspondingly tapered to enter and frictionally engage the marginal surface of the bore.

10. A syringe as set forth in claim 5 in which the piston is provided with an upwardly extending pin and the lower end of the rod is provided with a short piece of flexible tubing adapted to frictionally engage the surface of said pin.

11. A syringe comprising a tube, a piston slidment with the flexible bulb, the lower end of said member being disposed for engagement by the piston.

12. A syringe as set forth in claim 11 in whic the upper end of the rod is provided with an operating handle.

EDITH HOLTMAN. 

